Supplement 3 (1995)

This supplement is as close as possible to the published version [see Eur. J. Biochem., 1996, 237, 1-5]. If you need to cite this supplement please quote this references as its source.

This document contains further additions and amendments to Enzyme Nomenclature (1992), published by Academic Press, Orlando, Florida. Supplement 1 and 2 were published in Eur. J. Biochem.223, 1-5 (1994), and Eur. J. Biochem.232, 1-6, 1995. The entries marked with an asterisk are revisions of the corresponding entries in Enzyme Nomenclature (1992). Families of peptidases are referred to by use of the numbering system of Rawlings, N.D. & Barrett, A.J. (Methods Enzymol.244, 19-61 and 461-486, 1994; Methods Enzymol.248, 105-120 and 183-228, 1995). Comments and suggestions on enzyme classification and nomenclature may be sent to Prof. K. F. Tipton, Department of Biochemistry, Trinity College Dublin, Dublin 2, Ireland.

Comments: A homodimer. An integral protein of the plasma membrane of lymphocytes and other mammalian cells, in peptidase family S9. The reaction is similar to that of the unrelated X-Pro dipeptidyl-peptidase of lactococci

Reaction: Release of a C-terminal dipeptide, oligopeptideXaa-Xbb, when Xaa is not Pro, and Xbb is neither Asp nor Glu. Thus, conversion of angiotensin I to angiotensin II, with increase in vasoconstrictor activity, but no action on angiotensin II

Comments: A Cl--dependent, zinc glycoprotein that is generally membrane-bound. A potent inhibitor is captopril. Important in elevation of blood pressure, through formation of angiotensin II (vasoconstrictor) and destruction of bradykinin (vasodilator). Two molecular forms exist in mammalian tissues, a widely-distributed somatic form of 150- to 180-kDa that contains two non-identical catalytic sites, and a testicular form of 90- to 100-kDa that contains only a single catalytic site. Member of peptidase family M2

Reaction: Hydrolysis of unblocked, C-terminal dipeptides from oligopeptides, with broad specificity. Does not hydrolyse bonds in which P1' is Pro, or both P1 and P1' are Gly

Other names: Dipeptidyl carboxypeptidase

Comments: Known from E. coli and Salmonella typhimurium. A zinc metallopeptidase in peptidase family M3. Ac-AlaAla-Ala is a good test stubstrate [3]. Inhibited by captopril, as is peptidyl-dipeptidase A. Formerly EC 3.4.15.3, and included in EC 3.4.15.1

Reaction: Hydrolysis of γ-D-glutamyl bonds to the L-terminus (position 7) of meso-diaminopimelic acid (meso-A2pm) in 7-(L-Ala-γ-D-Glu)-meso-A2pm and 7-(L-Ala-γ-D-Glu)-7-(D-Ala)-meso-A2pm. It is required that the D-terminal amino and carboxy groups of meso-A2pm are unsubstituted

Other Names: Endopeptidase I

Comments: A 45-kDa metallopeptidase from Bacillus sphaericus, the substrates being components of the bacterial spore wall. A member of peptidase family M14. Endopeptidase II has similar activity, but differs in cellular location, molecular mass and catalytic mechanism [3]

Reaction: Hydrolysis of proteins to small peptides in the presence of ATP and Mg2+. α-Casein is the usual test substrate. In the absence of ATP, only oligopeptides shorter than five residues are hydrolysed (such as succinyl-Leu-TyrNHMec; and Leu-Tyr-LeuTyr-Trp, in which cleavage of the -TyrLeu- and -TyrTrp bonds also occurs)

Other Names: Endopeptidase Ti; Caseinolytic protease

Comments: An enzyme from bacteria that contains subunits of two types, ClpP, with peptidase activity, and ClpA, with ATPase activity. The ClpAP complex, which displays ATP-dependent endopeptidase activity, has the composition (ClpP14ClpA6)2 [4]. ClpP is a member of peptidase family S14

Reaction: Release of protein hormones, neuropeptides and renin from their precursors, generally by hydrolysis of -Lys-Arg bonds

Other Names: Prohormone convertase 3; Neuroendocrine convertase 1

Comments: A Ca2+-dependent enzyme, maximally active at about pH 5.5. Substrates include pro-opiomelanocortin, prorenin, proenkephalin, prodynorphin, prosomatostatin and proinsulin. Unlike prohormone convertase 2, does not hydrolyse proluteinizing-hormone-releasing-hormone. Unusually, processing of prodynorphin occurs at a bond in which P2 is Thr. Present in the regulated secretory pathway of neuroendocrine cells, commonly acting co-operatively with prohormone convertase 2. A member of peptidase family S8

Reaction: Release of protein hormones and neuropeptides from their precursors, generally by hydrolysis of -Lys-Arg bonds

Other Names: Neuroendocrine convertase 2

Comments: A Ca2+-dependent enzyme, maximally active at about pH 5.5. Specificity is broader than that of prohormone convertase 1. Substrates include pro-opiomelanocortin, proenkephalin, prodynorphin, proglucagon, proinsulin and proluteinizing-hormone-releasing-hormone. Does not hydrolyse prorenin or prosomatostatin, however. Unusually, processing of prodynorphin occurs at a bond in which P2 is Thr. Present in the regulated secretory pathway of neuroendocrine cells, commonly acting co-operatively with prohormone convertase 1. A member of peptidase family S8

Reaction: Hydrolysis of proteins and small molecule substrates, with a preference for Arg in P1

Other names: Arg-gingipain; Gingipain-1; Argingipain

Comments: A secreted endopeptidase from the bacterium Porphyromonas gingivalis. Strongly activated by glycine [1], and stabilized by Ca2+. Precursor molecule contains a haemagglutinin domain [2,3]. Misleadingly described in some literature as "trypsin-like", being a cysteine peptidase in family C25

Reaction: Hydrolysis of oligopeptides, with broad specificity. Gly or Ala commonly occur as P1 or P1' residues, but more distant residues are also important, as is shown by the fact that Z-Gly-Pro-GlyGly-Pro-Ala is cleaved, but not Z-(Gly)5 [4]

Comments: Known from E. coli and Salmonella typhimurium. A zinc metallopeptidase, in peptidase family M3, but differs from thimet oligopeptidase in lack of thiol-activation

Reaction: Hydrolysis of the -Trp21Val- bond in big endothelin to form endothelin 1

Comments: A phosphoramidon-sensitive metalloendopeptidase in peptidase family M13. An integral membrane protein predominantly of endothelial cells, which generates the potent vasoconstrictor endothelin 1 from its inactive precursor